Hamas office in Damascus told Xinhua on Monday that "we do not accept the accusation, we will continue our coordination with the Dubai police to complete the investigation."

Dubai police chief Dahi Khalfan Tamim said an internal "agent" of Hamas leaked the travel information of al-Mabhouh, which resulted in his assassination, calling on Hamas to launch an internal inquiry, the English newspaper of the United Arab Emirates (UAE) Gulf News reported on Sunday.

However, Hamas said Dubai police did not officially tell them anything on this subject.

The 50-year-old al-Mabhouh, a senior commander of Hamas military wing of Ezzedeen al-Qassam Brigades, was born in the Gaza Strip but has been living in Syria since 1989. He was found dead in his hotel room on Jan. 20, one day after he arrived in Dubai.

Mahmoud al-Zahar, a senior Hamas leader, said on Monday that 11 European passport holders are suspected to have been involved in the killing of al-Mabhouh.

Al-Zahar said the suspects include six Britons, one French, one German and three Irish nationals. Initial investigation showed that some of the suspects used fake passports from the European nations.